1. Field of the Invention
The present disclosure relates to pastes and methods of making a moisture determination of the paste during manufacture; optionally, the pastes comprise carbon nanotubes.
Carbon nanotubes (CNT) have many unique properties stemming from small sizes, cylindrical graphitic structure, and high aspect ratios. Carbon nanotubes possess outstanding material properties but are difficult to process and insoluble in most solvents. Historically polymers such as poly(vinylpyrrolidone) (PVP), poly(styrene sulfonate) (PSS), poly(phenylacetylene) (PAA), poly(meta-phenylenevinylene) (PmPV), polypyrrole (PPy), poly(p-phenylene benzobisoxazole) (PBO) and natural polymers have been used to wrap or coat carbon nanotubes and render them soluble in water or organic solvents. Previous work also reports single-walled carbon nanotubes (SWCNTs) have been dispersed with three types of amphiphilic materials in aqueous solutions: (i) an anionic aliphatic surfactant, sodium dodecyl sulfate (SDS), (ii) a cyclic lipopeptide biosurfactant, surfactin, and (iii) a water-soluble polymer, polyvinylpyrrolidone (PVP).
Conventional electro-conductive pastes are comprised primarily of polymeric binders which contain or have mixed in various amounts of electro-conductive filler such as finely divided particles of metal such as silver, gold, copper, nickel, palladium or platinum and/or carbonaceous materials like carbon black or graphite, and a liquid vehicle. A polymeric binder may attach the conductive filler to a substrate and/or hold the electro-conductive filler in a conductive pattern which serves as a conductive circuit. The liquid vehicle includes solvents (e.g., liquids which dissolve the solid components) as well as non-solvents (e.g., liquids which do not dissolve the solid components). The liquid vehicle serves as a carrier to help apply or deposit the polymeric binder and electro-conductive filler onto certain substrates. It is very helpful to be able to measure and control the water content of a CNT-based paste.